PM cuts short holiday to lead search for James Foley killer

EXECUTED: Missing American journalist James Wright Foley has reportedly been killed by the Islamic State [AFP/GETTY]

As Foreign Secretary Philip Hammond seemingly confirmed that the veiled man who speaks to the camera in the shocking execution video IS a Brit, the Prime Minister cut short his holiday in Cornwall to head back to Downing Street for meetings with intelligence chiefs from the UK and Amerca.

Looking tired and dishevelled as he exited his car outside Number 10, the PM went straight inside, not being drawn on any reaction to the video – which the FBI has confirmed is genuine.

He earlier said: "If true, the murder of James Foley is shocking and depraved.

"I will today chair meetings on the situation in Iraq/Syria."

British intelligence services are now trying to piece together evidence to identify the killer, who spoke with what a linguistics expert described as a London accent as he brandished the knife he used to behead his victim.

Dr Claire Hardaker told radio station LBC: "From what I can judge we seem to have definitely southern vowels in there, we've got some interesting pronunciations – he says Muslims in quite an interesting way.

"The way that you say it you kind of have a Z sound, but when he's doing it he's doing a 'muss', an unvoiced S so there's something interesting going on there...

"I think we are definitely looking at a British accent from the south – and probably from London."

BRUTAL: Foley sits on his knees before the executioner beheads him [REUTERS]

“He was an extraordinary son, brother, journalist and person”

Diane Foley

The killing has been condemned internationally, with France branding it a "cowardly assassination" and White House officials saying the US is "appalled".

Ukip leader Nigel Farage called on the Government to stop Britons who have gone to fight for IS from returning.

He said: "It would be totally unforgivable and unacceptable for UK nationals who have made the decision to go and fight for Islamic State militants in the Middle East to be permitted to return to the UK and quietly slide back into our communities to take advantage of all that modern Britain has to offer."

Foley's beheading was this morning described as an "appalling example of the brutality of this organisation" by the Foreign Secretary.

He told the BBC: "Certainly at first pass that's what it looks like and we will obviously want to investigate that further.

"We have been saying for a long time that there are a significant number of British nationals in Syria and Iraq operating with extremist organisations.

"That's one of the reasons why this organisation represents such a direct threat to the UK's national security.

"Many of these people may seek at some point to return to the UK and they would then pose a direct threat to our domestic security."

Mr Hammond said the intelligence agencies were tracking and monitoring Britons who could be involved with extremist groups in Syria and Iraq.

SEARCH: David Cameron cut short his holiday for meetings with intelligence chiefs [REUTERS]

He added: "This is a poison, a cancer, what's going on in Iraq and Syria and it risks spreading to other parts of the international community and affecting us all directly...

"This is something we have been tracking and dealing with for many, many months, I don't think this video changes anything it just heightens awareness of a situation which is very grave and which we have been working on for many months."

In June two men from Cardiff and a man from Aberdeen featured in an online recruitment video urging western Muslims to join the fighting with the Islamic State in Iraq and Greater Syria (Isis) group, now known as IS.

Nasser Muthana, 20, Reyaad Khan, 20, and Abdul Raqib Amin, 26, appeared in the video and are thought to be among more than 400 Britons fighting in Syria and Iraq.

The journalist's mother, Diane Foley, paid tribute to her son this morning and pleaded with IS extremists to not murder any more hostages.

She said: "We have never been prouder of our son Jim.

"He gave his life trying to expose the world to the suffering of the Syrian people.

"We implore the kidnappers to spare the lives of the remaining hostages.

"Like Jim, they are innocents. They have no control over American government policy in Iraq, Syria or anywhere in the world.

"We thank Jim for all the joy he gave us. He was an extraordinary son, brother, journalist and person."

EXTRAORDINARY: The journalist's mother paid tribute to her son [IG]

Foley, who was 40 when he died, went missing on November 22, 2012, and was last seen reporting from Syria.

In the disturbing video – which was posted on YouTube but has since been removed – Foley is seen kneeling in a desert-like environment at an unknown location as an IS fighter stands by his side dressed in black and with his face covered.

He then makes a statement to the camera, calling on his family, friends and loved ones to "rise up against my real killers, the US government".

He added: "For what will happen to me is only the result of their complacency and criminality".

RISK: Foreign Secretary Philip Hammond said IS were a threat to UK national security [PA]

The statement, during which he is seen to pause and take deep breaths, ended with him saying he wished he could see his family again.

The IS fighter standing next to him is then seen brandishing a knife before accusing America of "aggression towards the Islamic state".

He said: "You have plotted against us and gone far out of your way to find reasons to interfere in our affairs."

Foley is then beheaded before footage of another man – thought to be missing TIME journalist Steven Sotloff – is shown before the executioner claims Sotloff's fate "depends" on President Obama's "next decision".